top of page


In our introduction into the Pi (๐›‘) of a circle we have learnt that the relationship between the circumference of a circle and its diameter is always more than 3.

A more accurate result has been given as 3.14, and most calculators may have a key for ๐›‘.

We can understand that the circumference is also called the perimeter of a circle. This is because perimeter is the distance around an object.

The diameter is twice the radius.

Out of the ratio between the diameter and the circumference (๐›‘ = c/d), we can have the following formulae:

Circumference = ๐›‘ x diameter (2r)


Circumference = ๐›‘ x 2r


Circumference = 2 ๐›‘ r

Below is a video on the above explanation.

The next video is a tutorial on how to calculate circumference given the diameter, and vice versa.

bottom of page